Trends in asymmetric Michael reactions catalysed by tripeptides in combination with an achiral additive in different solvents

The potential of tripeptides 3, 6 and 12 as chiral catalysts for asymmetric Michael addition reactions in the presence of an achiral additive has been tested in different solvents (CHCl3, acetone, DMF, DMSO and the room-temperature ionic liquid [bmim]PF6). The dependence of yields and enantiomeric excesses on the solvent used has been demonstrated. The experiments show that the combination of additive and peptides provides a catalytic system that appears to be better than the sum of its parts.